Aircraft

A forthcoming decision by the US Federal Aviation Administration (FAA) is likely to initiate the largest mandated avionics buy in the history of aviation, one that could change the model for how government and private industry pay for safety and efficiency-boosting infrastructure in the future.

At issue is the FAA's proposed rule for Automatic Dependent Surveillance - Broadcast Out (ADS-B Out) surveillance systems, devices the agency says will cost the airborne segment - airlines and aircraft owners - anywhere from $1.27 billion to $7.46 billion to purchase and install over the next 12 years in return for $10 billion in cumulative benefits, primarily from fuel and time saved. The FAA calls ADS-B the backbone of its next generation air transportation system initiative.

Previous avionics rulemakings pale by comparison: The terrain awareness warning system rule, finalised in 2001, came in at $345 million the reduced vertical separation minima rulemaking, completed in 2005, was priced at $634 million. Both are expected to ultimately yield more than three times their cost in benefits, according to the FAA.

From the government's standpoint, ADS-B Out is a win-win proposition. The technology relays GPS position information from aircraft (hence the "out" in the name) to ground stations and ultimately to the FAA for surveillance, a data source that will allow the agency to do away with a large number of costly secondary surveillance radar systems. By moving away from radar, the FAA promises more accurate position reports which it says will allow controllers to trim unneeded spacing buffers between aircraft, increasing capacity and speeding up the system.

Under the proposed rule, by 1 January 2020, aircraft flying above 24,000ft (FL240 or 7,320m) will have to be equipped with a 1090MHz extended squitter (1090ES) system. Aircraft in controlled airspace flying below FL240 will have to use either a 1090ES or a universal access transceiver, a 978MHz device thought to be the most suitable for general aviation aircraft.

Is the gain worth the Pain?

Both systems will be required to transmit 15 data elements, several requiring flight crew entry. Included will be the length and width of the aircraft, its position, velocity, barometric altitude, call sign or tail number, emitter category (a measure of the severity of the wake vortex the aircraft produces) and a wealth of other information related to the status of onboard avionics or the aircraft itself.

Airlines are questioning whether the gain is worth the pain, at least in the mid-term. More valuable for airlines is the ADS-B "in" functionality, which the FAA has not yet addressed in a rulemaking. The feature brings into each aircraft the GPS position of all nearby aircraft, with a precision that could allow for self-spacing and other efficiency-boosting procedures. Though it would make sense to buy and install both options at the same time, the estimated cost to airlines alone would be on the order of $15 billion, says James May, president and chief executive of the Air Transport Association of America. "Congress and the FAA should make this programme a priority by creating financial incentives for accelerated deployment," he says.

The incentives he spoke of had been crafted by an aviation rulemaking committee brought together by the FAA to ponder the ADS-B rule early on. Among the ARC's suggestions: have the government pay for the certification, purchase and installation of the airborne equipment provide grants to owners and operators to purchase the equipment issue research and development credits to the avionics manufacturers who chose to develop, certify and build the units lower fuel taxes, landing and over-flight fees for users who equip, and provide users with interest-free loans to be paid back only after benefits have accrued.